1. Field of the Invention
The present invention relates to a disk for storing liquid samples and used to count and observe cells in the liquid samples, as well as to a counting observation apparatus for counting and observing cells through an optical microscope by use of the disk. More particularly, the present invention relates to a disk for storing liquid samples used to count and observe cells in the liquid samples which can be readily fabricated at low cost, as well as to a counting observation apparatus for counting and observing cells through an optical microscope by use of the disk which can be fabricated in a reduced size and at low cost.
2. Description of the Related Art
Many conventional disks for storing liquid samples and used to count and observe cells in the liquid samples are configured such that a cover member covers, from above, a lower structure in which a plurality of accommodation recesses for storing respective liquid samples are arranged radially (refer to, for example, Japanese Patent Application Laid-Open (kokai) No. 8-082590 and Japanese Patent No. 2731423). In this case, the lower structure and the cover member are fabricated from transparent glass or resin material. While the disk is rotated intermittently, counting and observing cells in the liquid samples stored in the accommodation recesses are performed sample by sample through a transmission microscope.
The lower structure having the plurality of liquid-sample accommodation recesses is fabricated from transparent glass or resin material by means of a forming process. Thus, finishing the liquid-sample accommodation recesses at dimensionally high accuracy is not easy. Since an illumination light source and an optical system oppose each other with a liquid sample located therebetween, the counting observation apparatus using the transmission microscope has a drawback that its size becomes large.
In order to avoid an increase in the size of a counting observation apparatus, there have been proposed counting observation apparatus for counting and observing cells by use of an incident-light microscope in which an illumination light source and an optical system are disposed on the same side in relation to a liquid sample, while a reflector is disposed behind the liquid sample (refer to, for example, Japanese Patent No. 3434064 and Japanese Patent Application Laid-Open (kokai) No. 2004-348104). However, the apparatus disclosed in Japanese Patent Application Laid-Open (kokai) No. 2004-348104 uses a nonrotatable, rectangular-parallelepiped-shaped container for storing a liquid sample, and the apparatus disclosed in Japanese Patent No. 3434064 does not mention a container for storing a liquid sample.